I wish we could just standardize on (say) 12 volts, with some barrel connector size that is currently unused. All cables that have the barrel must carry at least 250W. Current negotiation works like this:
All power supplies must tolerate over current by optionally voltage drooping to 5V for 100ms, then (mandatory) tripping a breaker if overcurrent persists. Devices can binary search on the current draw, or not (so long as they actually trip the breaker and don’t just cycle on and off at 10hz).
Plus on inside minus on outside for barrel connector.
Done. Forever. The complete spec could fit on a page.
so all cables and connectors rated for a bit over 20amps (i.e. more than your usual domestic socket, for reference what cable sizes that is), DC, with disconnection under load? That is highly impractical.
All power supplies must tolerate over current by optionally voltage drooping to 5V for 100ms, then (mandatory) tripping a breaker if overcurrent persists. Devices can binary search on the current draw, or not (so long as they actually trip the breaker and don’t just cycle on and off at 10hz).
Plus on inside minus on outside for barrel connector.
Done. Forever. The complete spec could fit on a page.